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add error checking

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Robby Findler 2013-05-04 19:53:35 -05:00
parent 05d429909f
commit 512d953a01
1 changed files with 13 additions and 0 deletions
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13
collects/racket/syntax.rkt
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@ -73,12 +73,25 @@
disappeared-uses))))
(define (syntax-local-value/record id pred)
(unless (identifier? id)
(raise-argument-error 'syntax-local-value/record
"identifier?"
0 id pred))
(unless (and (procedure? id)
(procedure-arity-includes? id 1))
(raise-argument-error 'syntax-local-value/record
"(-> any/c boolean?)"
1 id pred))
(let ([value (syntax-local-value id (lambda () #f))])
(and (pred value)
(begin (record-disappeared-uses (list id))
value))))
(define (record-disappeared-uses ids)
(unless (and (list? ids) (andmap identifier? ids))
(raise-argument-error 'record-disappeared-uses
"(listof identifier?)"
ids))
(let ([uses (current-recorded-disappeared-uses)])
(when uses
(current-recorded-disappeared-uses